Warm Melon and Prosciutto Salad - white wine vinegar

Ingredients

• 2 tablespoons white wine vinegar
• 1 teaspoon pink peppercorns, crushed
• 1 teaspoon Dijon mustard
• 1/2 medium shallot, thinly sliced
• 1/4 cup vegetable oil
• 1 tablespoon each of heavy cream and unsalted butter
• Salt and freshly ground black pepper
• 1/2 cantaloupe, peeled and cut into 1-inch cubes
• One 6-ounce bunch of watercress, large stems discarded
• 2 cups (1 1/2 ounces) baby spinach
• 3 ounces thinly sliced prosciutto ham
• 2 tablespoons pine nuts, lightly toasted
• Aged balsamic and buttered, toasted brioche, for serving